고출력 Nd:YAG UV레이저를 이용한 polyimide 층과 Cu-metal층의 가공상태에 대한 실험적 고찰 (Experimental investigation for ablation characteristics of polyimide layer and Cu-metal layer using high power Nd:YAG UV laser)

서지정보

· 발행기관 : 한국반도체디스플레이기술학회
· 수록지 정보 : 반도체디스플레이기술학회지 / 8권 / 4호 / 31 ~ 36페이지
· 저자명 : 최경진, 이용현

초록

In this paper, the laser cutting characteristics of the flexible PCB using high power Nd:YAG UV laser were investigated. A specific FPCB model was selected for the experiment. Test sheets were made, which had equal materials and layer structure to those of the outline(OL) region and the contact pad(CP) region in the FPCB. The experiment is made up of two stages. In the first stage of the experiment, the laser cutting fluence was found, which is the threshold fluence to cut the test sheets completely. The laser cutting fluence of the OL sheet is 1781.26~1970.16J/㎠ and that of the CP sheet is 2109.34~2134.34J/㎠. In the second stage, cutting performance and its qualities were analyzed by the experiment. The laser cutting performance remained almost unchanged for all laser and process parameter sets. The average cutting width (top side/bottom side) of the OL sheet was 40.45μm /11.52μm and that of the CP sheet was 22.14μm/10.93μm. However, the laser cutting qualities were different according to the parameters. The adjacent region of the cutting line on the OL sheet was carbonized as the beam speed was low and the overlap coefficient was high. The surface quality around the cutting line of the CP sheet was about the same. Carbonization and debris occurred on the surface of the cutting line. As a result of the experiment, the cutting qualities were better as the overlap coefficient was made low and beam speed high. Therefore, the overlap coefficient 2 or 3 is proper for the FPCB laser cutting.

영어초록

In this paper, the laser cutting characteristics of the flexible PCB using high power Nd:YAG UV laser were investigated. A specific FPCB model was selected for the experiment. Test sheets were made, which had equal materials and layer structure to those of the outline(OL) region and the contact pad(CP) region in the FPCB. The experiment is made up of two stages. In the first stage of the experiment, the laser cutting fluence was found, which is the threshold fluence to cut the test sheets completely. The laser cutting fluence of the OL sheet is 1781.26~1970.16J/㎠ and that of the CP sheet is 2109.34~2134.34J/㎠. In the second stage, cutting performance and its qualities were analyzed by the experiment. The laser cutting performance remained almost unchanged for all laser and process parameter sets. The average cutting width (top side/bottom side) of the OL sheet was 40.45μm /11.52μm and that of the CP sheet was 22.14μm/10.93μm. However, the laser cutting qualities were different according to the parameters. The adjacent region of the cutting line on the OL sheet was carbonized as the beam speed was low and the overlap coefficient was high. The surface quality around the cutting line of the CP sheet was about the same. Carbonization and debris occurred on the surface of the cutting line. As a result of the experiment, the cutting qualities were better as the overlap coefficient was made low and beam speed high. Therefore, the overlap coefficient 2 or 3 is proper for the FPCB laser cutting.

참고자료

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